Doubts raised about CRISPR gene-editing study in human embryos

Alternative explanations challenge whether technique actually fixed a genetic mutation as claimed

Doubts have surfaced about a landmark paper claiming that human embryos were cleared of a deadly mutation using genome editing. In an article1 posted to the bioRxiv preprint server on 28 August, a team of prominent stem-cell scientists and geneticists question whether the mutation was actually fixed.

The 2 August Nature paper2, led by reproductive biologist Shoukhrat Mitalipov at the Oregon Health and Science University in Portland, described experiments in dozens of embryos to correct a mutation that causes a heart condition called hypertrophic cardiomyopathy…NATURE: